This is a valid concern I also reacted a little bit on. One thing to note though is that it is often possible to tell such chains to be lazy and only collect th

This is a valid concern I also reacted a little bit on. One thing to note though is that it is often possible to tell such chains to be lazy and only collect the end result at the end without ever generating any intermediary arrays. Which require the author to actually have an idea how big the numbers are, but that is very often the case regardless of how you write your code.